[postgis-devel] ST_asGML strictness

[strk]

On Mon, Mar 22, 2010 at 11:56:47PM +0100, Olivier Courtin wrote:
> 
> On Mar 22, 2010, at 11:00 PM, strk wrote:
> 
> Hi,
> 
> >I'm in the process of adding optional 'prefix' parameter
> >to the ST_asGML family of functions.
> 
> Well i was also curently working on it...
> 
> Still have to debug/cunit and document it

Oops, I've already committed the liblwgeom/ part and cunit.
Sorry if I didn't announce the start of this.

> >In doing so, I was thinking to just add the new parameter
> >to the end of the existing ones, but that would force anyone
> >willing to add a prefix to specify all args.
> 
> Same, same...
> 
> Except that this parameter is optional,
> so it keep the compatibilty with older versions
> 
> It becomes:
>   -> a specific option (4 th parameter) to remove ns prefix
>        if we want/need no prefix at all
> 
>   -> the 5th optional parameter to specify something else
>        than ns prefix: gml
> 
>   -> in any other cases (so like now), prefix is: gml
> 
> 
> Thoughts ?

I kind of don't like the fact it would then be possible to say
"no prefix" with 4th arg and still pass a 5th arg with another
prefix. Also I don't find the 'options' parameter very friendly
to use. 

But anyway my solution also doesn't convince me much, it being:
	omitted or null prefix : <prefix> == "gml"
	non-empty prefix       : <prefix> + :
	empty prefix           : no prefix (and no colon)
what doesn't convince me much with this is the impossibility
to get a prefix consisting of an empty string + a ':' character.

So all in all I'm happy if you take care of the interface part
and am fine with your solution.

--strk;

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